中国岩黄耆属(豆科)种皮纹饰及其系统学意义

利用扫描电镜观察了国产岩黄耆属(Hedysarum L.)18个种(含3个居群)的种皮纹饰。结果表明: 岩黄耆属种皮纹饰性状在种的划分上具有重要的分类学意义。依据种皮纹饰特性, 大致分为光滑型和粗糙型2大类型以及断棱状、嚼烂状、龟纹状、网纹状与细网状5个亚型。依据其划分的类型及亚型, 种皮纹饰呈现出从断棱状、细网状到光滑状的演化趋势, 从而阐明了种皮纹饰在岩黄耆属系统演化上的重要意义。     

卫矛属冬青卫矛组种皮和假种皮微形态研究

利用扫描电子显微镜对冬青卫矛组(Sect.Ilicifolia Nakai)13种以及卫矛属其他组6种植物的种皮和假种皮微形态特征进行了研究.结果表明,冬青卫矛组植物种皮和假种皮的纹饰主要为网纹型,大致可划分为4个类型:(1)种皮纹饰为复网纹型,网眼隆起;(2)种皮纹饰为复网纹型,网眼中部下陷;(3)种皮纹饰为网纹型,假种皮嚼烂状;(4)种皮纹饰为网纹型,假种皮网纹状.种皮和假种皮微形态特征在对近缘种的分类上提供了一定的参考依据.     

中国小檗科5属植物种子形态研究

利用解剖镜和扫描电镜对小檗科5属(小檗属、十大功劳属、鬼臼属、山荷叶属和红毛七属)40种2变种植物种子形态进行观察。研究结果表明:小檗科植物种子颜色多为黄褐色、红棕色至黑色,形状多样;种皮纹饰可分为网纹型、网纹—梯纹型、梯纹型和嚼烂状4种类型,其中网纹型又可划分为7个亚型。种子球形、种脐位于种子侧面近中部可作为红毛七区别于其他属种子的重要形态特征。根据种皮微形态特征,探讨了种子形态在小檗科内的系统学意义,并推测了种皮纹饰的可能演化路线。种子形态支持小檗属和十大功劳属的近缘关系,认为鬼臼属(八角莲属)较山荷叶属分化更早,但不支持Ahrendt对小檗属下组和亚组的划分。     

国产菟丝子属种子形态的观察

本文观察了中国产菟丝子属种子的形态和种皮表面的超微结构。菟丝子属种子表面特征如下： 种脐呈衣领状突起或与晕轮面平齐或下陷;晕轮细胞呈近放射状排列或网状排列或不规则排列;种皮 表面呈条纹状纹饰或脑纹状纹饰或网状纹饰,纹饰上有时具瘤状突起或块状附属物。根据上述特征,可将菟丝子属种子分成三种类型。种皮纹饰可作为分类鉴定和种子检疫的依据。     

十八个产地兴安落叶松种皮微形态的研究

对18个不同产地的兴安落叶松种皮微形态进引扫描电镜观察。结果表明,种子背面均为条网状纹饰,腹面为拟脑状纹饰,种孔周围呈条带状皱波纹饰,种孔周围形态存在三种类型。种皮纹饰在种内基本上是稳定的,其中腹面纹饰较背面纹饰的变异幅度大。种皮纹饰特征可以作为兴安落叶松种子鉴定的依据之一。     

四棱草属比较形态及其分类系统位置的研究──Ⅳ．四棱草属及其近缘属叶表皮结构特征

四棱草属Ｓｃｈｎａｂｅｌｉａ及其近缘属筋骨草属Ａｊｕｇａ,香科科属Ｔｅｕｃｒｉｕｍ（唇形科Ｌａｂｉａｔａｅ）,获属Ｃａｒｙｏｐｔｅｒｉｓ,大青属Ｃｌｅｒｏｄｅｎｄｒｕｍ（马鞭草科Ｖｅｒｂｅｒｎａｃｅａｅ）５属,６种代表植物的叶表皮细胞形状、气孔类型和毛状体类型的比较研究结果是：（１）叶上表皮细胞形状是深波纹状不规则形,浅波纹状不规则形和浅波纹状四边形;（２）气孔类型是不规则型,平列型,横列型和等位横列型。（３）毛状体类型属单毛和鳞片毛二种类型。根据上述特征及其分布规律,作者认为四棱草属在唇形科与马鞭草科系统演化的框架里,是处于中间过渡类型的位置。     

中国广义冰岛蓼属果实形态特征

应用扫描电镜对冰岛蓼属（Koenigia L.）8个物种的果实形态与果皮微形态进行了观察。结果表明,这些果实可分为3类：类型Ⅰ：瘦果长卵形至宽卵形,中部或中上部最宽,双凸镜状或3棱状,棱脊有或无;表面粗糙或光滑,具纵向断棱状纹饰,或具波状纹饰,这种类型有冰岛蓼、铜钱叶蓼、青藏蓼、大铜钱叶蓼4种;类型Ⅱ：瘦果卵形,中部膨大,具有3棱脊,但棱脊不显著。这种类型仅小叶蓼1种;类型Ⅲ：瘦果卵形,中间最宽但不膨大,具有3棱脊,且棱脊显著;表面光滑,具多皱纹饰,或凹凸不平纹饰,或具疣状纹饰,这种类型包括细茎蓼,蓝药蓼和柔毛蓼3种。研究结果支持将柔毛蓼与蓝药蓼作独立分种处理、而冰岛蓼与青藏蓼关系很近。     

十大功劳属植物种子形态研究

利用光镜(LM)和扫描电镜(SEM)对十大功劳属24种植物的种子形态进行观察。结果发现十大功劳属植物种子颜色为黑色,长3.4～6.7mm,宽1.7～3.5mm,属大型种子,形状多样;外种皮纹饰为网纹状,网眼形状、大小及网脊粗细、凸凹在不同类群间不完全相同,种内变异稳定,据此可将十大功劳属植物种皮纹饰划分为9种类型。研究结果表明:种子形态在十大功劳属内具有重要的系统学意义,但不支持Ahrendt将十大功劳属下分为2个groups,4个sections,14个subsections的观点。     

中国紫葳科花粉形态的研究

对紫葳科18属27种花粉进行了光镜和扫描电镜的观察,其中有些种是第一次观察或报道。紫葳科花粉明显地属多型花粉,萌发孔类型和纹饰特征多种多样。萌发孔基本上可分为3（－4）沟,3（－4）孔沟,3孔,多沟及散沟等类型;纹饰则可分为皱波状饰,穴状纹饰,穴－网状纹饰,网状纹饰,刺状纹饰以及表面光滑等。值得注意的是在菜豆树属Rademoachera Zoll.et Moritzi中,菜豆树R．sinica和滇菜豆树R.yunnanensis虽为同一个属,但其萌发孔类型和纹饰特征截然不同,菜豆树花粉为3孔,具网状纹饰;而滇菜豆树花粉为3孔沟,具穴状纹饰。就花粉形态学而言,紫葳科也许是多元发生的。     

莎草属果皮微形态特征是及其分类学上的意义

首次报道了在立体显微镜及扫描电子显微镜下对莎草属１４种,２变种植物果皮微形态特征的观察结果。根据纹饰特点的不,可分为三种类型：（１）网－瘤状复合纹饰;（２）网状纹饰;（３）疣状纹饰。莎草属植物在果皮微形态特征上存在的种间差异可为种的划分提供依据,并为探讨该属的系统演化提供有价值的资料。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.